Implement PlatformUtil::OpenExternal() so that mailto: can work

chrome/android/java/src/org/chromium/chrome/browser/PlatformUtil.java

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.chrome.browser;
+
+import android.content.Context;
+import android.content.Intent;
+import android.net.Uri;
+
+import org.chromium.base.ApplicationStatus;
+import org.chromium.base.annotations.CalledByNative;
+
+/**
+ * Utility class for providing platform functionalities.
+ */
+public class PlatformUtil {
+    @CalledByNative
+    private static void launchExternalProtocol(String url) {
+        if (url.startsWith("mailto:")) {
+            Context context = ApplicationStatus.getApplicationContext();
+            Intent intent = new Intent(Intent.ACTION_SENDTO, Uri.parse(url));
+            intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

[Ted C, 2015/09/04 17:32:26]

should we add:

intent.addCategory(Intent.CATEGORY_BROWSABLE);

I don't know if that is explicitly required for SENDTO, but it is started by the
browser so it seems like the right thing to do?

[qinmin, 2015/09/04 17:51:38]

Done.

+            context.startActivity(intent);

[Ted C, 2015/09/04 17:32:26]

I would catch ActivityNotFoundException just in case here.

[qinmin, 2015/09/04 17:51:38]

Done.

+        }

[Ted C, 2015/09/04 17:32:26]

should we be sending a generic view intent in the else case or is this truly
only for mailto?

[qinmin, 2015/09/04 17:51:38]

Changed the Intent action to ACTION_VIEW and removed the if statement, so all
other types of url will be handled by the generic handler.

+    }

[Ted C, 2015/09/04 17:32:26]

And looking a bit more at the intent class, it looks like we might be able to
VIEW even for mailto:

http://developer.android.com/reference/android/content/Intent.html#ACTION_VIEW

So maybe this can be even more generic?

[qinmin, 2015/09/04 17:51:38]

Done.

+}